Panel lamp with terminal bases



May 24, 1966 A. F. PATE ETAL PANEL LAMP WITH TERMINAL BASES 2 Shets-Sheet 1 Filed May 1, 1961 United States Patent 3,253,176 PANEL LAMP WITH TERMINAL BASES Albert F. Pate, Wickliife, Robert A. Kuebler, Cleveland Heights, and Harold R. Kestner, Mayfield Heights,

Ohio, assignors to General Electric Company, a corporation of New York Filed May 1, 1961, Ser. No. 106,827 19 Claims. (Cl. 313-204) This invention relates to fluorescent panel lamps and more particularly to bases or terminal structures therefor.

In fluorescent panel lamps, the discharge path is a labyrinthine channel formed between two vitreous components sealed together along their margins. Such lamps provide a relatively long discharge in a small area which is an advantage from the point of view of compactness of source and ease of handling. They offer what may be described as an area light source as against a line source as is the case with the usual elongated fluorescent lamp.

In many of the applications presently visualized'for a panel lamp, it is intended that only one face of the lamp be exposed to View. For instance, it is contemplated that panel lamps be made in modular sizes corresponding to the dimensions of standard ceiling tiles. Alternatively, it is contemplated that panel lamps be used in shallow fixtures. In either case, the lower plate, which may be referred to as the faceplate of the lamp, is exposed to view and it is desired that no connectors or connecting wires mar its appearance. Also to carry through the modular concept, the base or terminal structure and the cooperating connector must fit within the modular dimensions and not project beyond them. This also permits the closest possible edge-to-edge mounting of the lamps.

It is desirable of course to have a base structure and cooperating connector which is electrically reliable and convenient to use. Exposed live conductors must be avoided. The bases must be firmly attached to the lamp, reasonable in cost and amenable to mass production techniques.

The object of the invention is to provide a base terminal structure and assembly with a fluorescent panel lamp having to an acceptable degree the above-outlined desirable attributes.

The lamp is formed by sealing two molded glass plates, the faceplate and the backplate, together along their margins. In the square or rectangular panel lamp, the sealed margins provide a flat marginal ledge running along the four sides of the lamp. The general terminal structure and connector scheme followed is in accordance with that described and claimed in copending application Serial No. 108,704, now Patent No. 3,198,943, of John M. Pistey, filed of even date herewith, entitled Connector, and as signed to the same assignee as the present invention. That scheme involves placing terminal structures at two corners of the lamp in facing relationship and utilizing a spring loaded bar-type connector to engage them.

The present invention provides a base terminal structure and assembly which implement the Pistey concept. A pair of base structures are provided and seated in spacedapart relationship on the marginal ledge on one side of the lamp. They are engageable by a spring-loaded bar-type connector which would then likewise overlie the ledge. In a preferred embodiment, each terminal structure consists of two main parts. One part consists of an insert which carries the terminals proper which are electrically connected to the electrodes of the lamp. The other part consists of a housing which accommodates and supports the insert and which is fastened to the vitreous lamp structure proper. The insert is provided with a pair of terminal pins and is accommodated in the housing by sliding it into a suitable blind well therein, an aperture in the housing giving access to the pins for the connector. The

housing may be attached to the lamp structure by means of clips which inter-engage the marginal ledge and projecting feet forming part of the housing, or else by suitable cements. The terminals or pins are engageable by longitudinal displacement of cooperating connector terminals along the marginal ledge.

the backplate with one base structure mounted in place I and the other dis-assembled with the immediately adjacent vitreous structure cut away to reveal the internal construction.

FIG. 2 is a side or end view of the lamp with reference to FIG. 1.

FIG. 3 is a fragmentary plan view of the lamp showing the base structures with the bar type connector latched in place.

FIG. 4 is a side view partly sectioned through one base structure and the connector, taken along line 4-4 of FIG. 3.

FIG. 5 is a front end view, partly sectioned, of one of the base structures taken along line 55 of FIG. 3.

FIGS. 6 and 7 are perspective views of clips which may be used for attaching the bases to the lamp.

FIGS. 8 and 9 are plan and side elevation views of a modified base structure.

Referring to the drawing and more particularly to FIGS. 1 and 2, the illustrated six-channel lamp 1 is in the form of a generally flat square panel made up of a pair of complementary molded glass components or plates 2, 3. The lower component 2. forms the underside or faceplate of the lamp which is exposed to view when the lamp is mounted in its fixture or incorporated into a ceiling. The upper component 3 which may be referred to as the backplate is molded or blown to define, in cooperation with the faceplate, a winding or labyrinthine discharge channel or passage by means of six parallel grooved sections or channelways 4 extending side by side and joined together at alternate ends, as at 5 where the lengthwise partitions 6 end, thereby forming a continuous grid-like channel. Both plates may be formed from fiat sheets of glass by any suit able means, for instance by vacuum molding. The faceplate 2 is provided with a plurality of shallow embossments 7, which may be of square outline in plan view, giving it somewhat the appearance of a quilt or checkerboard. The quilting of the faceplate improves the appearance and increases the strength of the assembly.

The edges of the faceplate and backplate are hermetically sealed together along the outer periphery 9 which thus forms a marginal ledge running around the four sides of the lamp. The sealing of the plates may be done either directly by fusion 'of the glass or through the use of a lower melting point soldering glass. Along the internal junctures 6 where the glass components abut together tomake partitions defining the labyrinthine discharge chan nel, the vitreous components may be sealed together if desired but it is not essential that this be done. Provided there is a close tight fit along the junctures, the electric discharge or arc will not leak through and short circuit at the partitions but will follow the labyrinthine channel from end to end.

The lamp is provided with discharge supporting electrodes at opposite ends of the channel. One electrode is seen in FIG. 1 where the backplate is cut away and comprises a coiled coil filament 10 of tungsten wire coated with alkaline earth electron-emitting oxides. The filament is supported across inleads 11, 12 which are sealed through the glass of the marginal ledge 9 where the faceplate and backplate are fused together. The glass bead bridge 13 is a spacer and stiifener to prevent strain on the filament, particularly prior to sealing into the vitreous lamp assembly. The upper glass component or backplate is notched inwardly from the outer edge at 14 and 15 in order to permit the outwardly projecting ends of the inleads to be turned up for connection to the base terminals. This avoids taking the inleads all the way to the outer edge of the marginal ledge where they might present a shock hazard. The electrodes are preferably of the low thermal capacity rapid start type which are preheated at starting by passing current therethrough, but other types of electrodes with other inlead sealing techniques may of course be used.

The lamp contains an ionizable atmosphere including a starting gas or mixture of one or more of the inert rare gases of Group of the Periodic Table at a low pressure, for instance argon at a pressure of 0.5 to 5, preferably 2 to 3, millimeters of mercury, along with mercury vapor. The quantity of mercury added exceeds that vaporized during normal operation of the lamp wherein it exerts a partial pressure in the range of 2 to 10 microns, more commonly to 8 microns for optimum generation of 2537 A. radiation. This radiation energizes a phosphor coating applied to the inside surfaces of the backplate and faceplate, the phosphor in turn producing visible light. The phosphor may be applied more sparingly on the faceplate, or alternatively a reflecting coating may be applied to the backplate, to cause the lamp to emit a greater proportion of its light downwardly through the faceplate than through the backplate.

The two base terminal structures proper are indicated at 17 and are arranged to seat near opposite ends of the marginal ledge 9 on the electrode side of the lamp and to overlie the notches 14, 15 at the points of emergence of the inleads. The base structure consists of two principal parts, the insert 18 and the external housing 19. Both parts are made of an insulating material, preferably a thermoplastic material which is readily molded such as white urea compound. The insert 18 is in the form of an upstanding block with a forwardly projecting foot 20. It is provided with a pair of spaced contacts in the form of horizontally directed tubular contact pins 21, 22. The pins have rounded front ends, intermediate shouldered ridges at 23 for locking against the front face of the insert, and upset rear ends which are embedded in the plastic at molding. The pins are accurately located vertically above the slightly inclined upper face of the foot which provides a seating surface for the terminal block of the connector to be described hereinbelow. In the assembly of the base structures to the lamp, the lead wires are initially connected to the contact pins of the insert as illustrated at 11, 12 on the left hand side of FIGS. 1 and 2. The connection of the lead wires to the pins may be done by soldering or welding, or in any other convenient manner. An angled slot at 24 in the rear side of the base of the insert facilitates-bringing lead 11 up from notch 14.

v The external housing 19 is in the form of an elongated block with a flat front end or face at 25 with an aperture therethrough to give access to the contact pins of the insert, and a curved or streamlined rear end wall at 26 which, for neatness of appearance, conforms generally to the curvature of the outer grooves or channelways in the backplate of the lamp. The side walls are generally straight and are extended forwardly as projecting wings or guards 27 on each side of the front face. A generally rectangular cavity or blind well 28 (best seen in FIG. 8) extending vertically upwards from the bottom wall is provided within the body of the housing to the rear of the front face for accommodating the insert. The well is open at the bottom but closed at the top. A narrower blind slot 29 extends through the housing behind the well 28 and up from the bottom wall and provides a passageway for the upper inlead 12.

The procedure for assembling the base components involves first connecting the lead wires to the contact pins of the insert 18. The external housing 19 is then pressed down over the insert so that the insert enters the blind well 28. The housing is provided with projecting feet 30, 31 at opposite longitudinal ends, each foot having a flat depressed portion or notch 32 and a deeper furrow 33 at the inner end, as best seen in FIG. 8. The feet are engaged by generally C-shaped springy metal clips 34, shown in FIG. 6. The clip comprises upper and lower horizontal arms 35, 36 provided with inwardly turned lips 37. The upper arm and its lip engage the notch and furrow in the foot of the base. The lower arm and its lip engage in a similar notch and furrow molded in the glass in the underside of the marginal ledge 9 of the lamp, as indicated at 38, 39 in FIG. 1. The marginal ledge is also preferably laterally notched as indicated at 40 to assure flush edge seating of the clips. The front clip is attached laterally and the rear clip is attached longitudinally.

In order additionally to secure the base structure in place, each housing may be provided with a lateral tang 41 which is entered into the slot or cavity between the outermost channelway 4 in the backplate of the lamp and that next to it. The tang is desirably hollow, that is slotted internally as indicated at 42 in order to achieve a more resilient engagement with the glass walls of the grooves. Where the base structures are attached to the marginal ledge by means of the metal clips 34, a very strong attachment is achieved even without the lateral tangs. Therefore the tangs 41 are not essential and may be dispensed with, as in base structure 17a illustrated in FIGS. 8 and 9.

However itis also possible to cement the base structure to the lamp by utilizing a suitable adhesive compatible with both the relatively high expansion coeflicient of the plastic of the base structure and the relatively low expansion coeflicient of the glass of the lamp structure. Where an adhesive is used, the projecting feet 30, 31 of the external housing 19 may be dispensed with but in this case the lateral tang 41 is desirable. Preferably the tang itself is also cemented to the glass of the lamp in the valley between the channelways.

When both base terminal structures are mounted on the lamp, they provide a pair of aligned and mutually facing terminal pins at opposite ends of the marginal ledge. These pins may then be engaged by means of a telescopic bar type connector 43 which is positioned to overlie the marginal ledge 9 as indicated in FIGS. 3 and 4. The connector comprises a rectangular metal housing 44 provided with similar terminal blocks at opposite ends, one block 45 being fixed to the housing and the other block 46 being slidable relative to the housing and biased outwardly by means of a spring 47. The blocks 45, 46 are preferably made of a readily molded thermoplastic material such as white urea compound. They are provided with apertures in which are inserted terminal strips 48, 49 for engaging the contact pins 21, 22 of the bases. The terminal strips are connected to conductors or wires indicated at 50 by means of which circuit connections are made to the ballast for energizing the lamp. The bar connector may be latched in place with one hand while the lamp is held in the other. The specific structure of the bar type connector 43 is more fully described and is claimed in the aforementioned copending application of John M. Pistey. However, it is also possible to use two separate connectors to engage the two spaced base structures.

In order to facilitate starting of discharge lamps such as fluorescent lamps, it is frequently desirable to have a conductive member, sometimes known as a starting aid, disposed in capacitive relationship to the discharge channel of the lamp. Such members may take various forms,

envelope, or a conductive strip or paint extending along the lamp, or part of the fixture extending in close proxi mity to the lamp envelope. It may be desirable to ground the starting aid or alternatively to apply an AC. voltage thereto, the choice depending upon the starting voltage requirements of the lamp. With the present fluorescent panel lamp construction, the starting aid is conveniently provided in the form of conductive strips 51 which are applied to the outside of the backplate over the partitions 6, that is in the valleys between the channeliways 4. As illustrated, the conductive strips are applied in three of the valleys, the two outervalleys and the middle valley. All the strip sections are joined together by another strip 52 which overlies the marginal ledge 9 (FIG. 1). The strips may be made of any suitable conductive material which may be adhered to the glass, for instance a silver paint or a graphite suspension or if preferred a vapor-deposited metal layer. Another material which may be used'is a self-adhesive tape provided with a conductive metal backing.

It is desired to make a circuit connection to the conductive strip and to this end, at least one of the terminal blocks of the connector, block 45 in this case, is provided with a springy bottom contact 53. The bottom contact may engage directly the conductive strip 5-2 overlying the marginal ledge. However in order to guard against abr-asion, it is preferred to provide a metal terminal band 54 which is disposed to overlie the ledge strip 46 and which in turn is engaged by the bottom contact 47 of the connector. The terminal band 54 is provided with a hooked end which is accommodated in a recess in the bottom face of the base terminal housing; it is thereby locked in place and pressed resiliently against conductive strip 52 overlying the ledge.

With clip 34 illustrated in FIG. 6, it is necessary to provide the cooperating notch and furrow in the underside of the glass ledge. Depending upon the technique used for sealing together the faceplate and the backplate, it may be difiicult to mold these shapes in the underside of the glass ledge. Also when the furrow is molded in the underside, there is a tendency to form a protuberance in the upper side directly opposite. The glass ledge is then no longer flat on the topside and this may create a problem in regards to seating the base thereon. FIG. 7 shows in perspective view an alternative form of clip 56 which resolves this problem. In this clip, the lowermost arm 57 is straight and is not provided with a lip. The uppermost arm 58 is provided with a downwardly turned lip 59 which engages the furrow in the foot of the plastic base housing in the same fashion as previously described. The clip is provided with an intermediate arm 60 which is offset to one side of the uppermost arm but nevertheless overlies a part of the lowermost arm. The spacing be tween the intermediate and the lowermost arms is such as to engage the glass ledge 9, and the intermediate arm is provided with a downwardly turned lip 61 which locks in a furrow now formed in the topside of the glass ledge. Thus the problem of distortion of the glass ledge resulting from the molding of a furrow in the underside is avoided, and at the same time the base structure is effectively locked in place.

It is also possible to use various combinations of cements and clips in lieu of an all-clip or all-cement fastening. For instance, a clip similar to C-shaped clip 34 may be used but having an inturned lip 37 on the upper arm only which engages in the foot of the base housing. In this case since the lower arm of the clip does not have an inturned lip and is therefore not locked to the glass ledge, the clips will prevent the base housing from turning or twisting but will not prevent sliding of the base relative to the ledge. As regards sliding, the tendency is mainly in a longitudinal direction relative to the ledge due to the pressure exerted on the base structures by the spring-biased bar connector. Therefore the lateral tang 41 is advantageously used to resist such pres- 6 sure. Finally an adhesive or cement is provided between the ledge and the bottom of the base housing, but the burden imposed on this adhesive is now greatly reduced and it need only provide the balance of the restraint needed to firmly secure the base in position.

It is desirable that the engagement of the bar connector in the base structures be strong enough to permit the panel lamp to be supported by the bar connector, as in handling, even though the practice is not recommended. The base structure 17a shown in FIGS. 8 and 9 has been modified to this end. The external housing is provided with a forwardly projecting brow or top wall portion at 62. The aperture giving access to the contact pins is now completely surrounded. When the terminal block (suitably reproportioned) of the bar connector enters the aperture, it is now engaged by wall surfaces of the base structure on all four sides and the desired support is achieved without endangering the contact pins. The base structure shown in FIGS. 8 and 9 is intended for an all-clip fastening and the lateral tang has been eliminated.

While certain specific embodiments of the invention have been illustrated and described in detail, they are intended by way of example only. Modifications will readily occur to those skilled in the art, as for instance the adaptation of similar structures to part of the curved ledge around a circular panel lamp. It is intended by the appended claims to cover any such falling .within the spirit of the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. A panel lamp comprising a generally flat vitreous envelope having a vitreous marginal ledge extending along a side, and a pair of base terminal structures spaced longitudinally apart, seated on and attached to said ledge, said base structures having terminals engageable by longitudinal displacement of cooperating connector terinals along said ledge.

2. A panel lamp comprising a generally flat rectangular vitreous envelope having a vitreous marginal ledge extending therearound, and a pair of base terminal structures seated on and attached to said ledge on one side of said envelope, said base structures being disposed in mutually facing relationship near opposite ends of said ledge and having terminals engageable by longitudinal displacement of cooperating connector terminals along said ledge.

3. A panel lamp comprising a generally fiat vitreous envelope having a vitreous marginal ledge extending along a side, and a pair of base terminal structures spaced longitudinally apart, seated on and attached to said ledge, said base structures having terminals in the form of longitudinally extending, aligned and mutually facing contact pins. A

4. A panel lamp comprising a generally fiat vitreous envelope having a vitreous marginal ledge extending along a side, and a pair of base terminal structures spaced longitudinally apart, seated on and attached to said ledge, said base structures being disposed in mutually facing relationship on said ledge and having terminals in the form of longitudinally extending, aligned and mutually facing contact pins.

5. An electric discharge panel lamp comprising a vitreous envelope formed of a backplate and a faceplate sealed together along their margins and together defining a labyrinthine discharge channel, said sealed margins providing a vitreous ledge along at least one side of said lamp, and a pair of base terminal structures seated on and attached to said marginal ledge near opposite ends thereof, each base structure comprising an elongated block of insulating material having a terminal projecting from its front face, said base structures being disposed with their front faces facing each other across said ledge.

6. An electric discharge panel lamp comprising a vitreous envelope formed of a backplate and a faceplate sealed together along their margins and together defining a labyrinthine discharge channel, said sealed margins providing a vitreous ledge along at least one side of said lamp, electrodes sealed into the ends of said discharge channel next to said marginal ledge, and a pair of base terminal structures seated on and attached to said marginal ledge at opposite ends thereof, each base structure comprising an elongated block of insulating material having a pair of contact pins projecting from its front face and connected to one of said electrodes, said base structures being disposed with their front faces facing each other across said ledge and with their contact pins in alignment.

7. An electric discharge panel lamp comprising a generally flat vitreous envelope formed of a backplate and a faceplate sealed together along their margins and together defining a labyrinthine discharge channel, said sealed margins providing a vitreous ledge along at least one side of said lamp, electrodes sealed into the ends of said discharge channel next to said marginal ledge, and base terminal structures seated on and attached to said marginal ledge at opposite ends thereof, each base structure comprising an insert provided with terminals connected to the adjacent electrode .and a housing provided with a well accommodating said insert and having an opening giving access to said terminals.

8. A fluorescent panel lamp comprising a generally fiat rectangular vitreous envelope formed of a backplate and a faceplate sealed together along their margins, said backplate having a plurality of parallel interconnected grooved channelways formed therein to define a labyrinthine discharge channel, said sealed margins providing a vitreous ledge extending around said envelope, electrodes supported in the ends of said discharge channel, and a pair of base terminal structures seated on and attached to said marginal ledge near opposite ends thereof on one side of said envelope, each base structure being in the form of an elongated block of insulating material having a generally fiat front face with an aperture therethrough, generally straight side walls extending forwardly into projecting wings on each side of the front face, a'top wall extending back from the front face and curving smoothly down to the rear to form the rear end wall with a curvature approximately matching that of the outermost grooved channelways in said backplate, and a pair of spaced contact pins projecting forwardly of said front face between said wings.

9. A fluorescent panel lamp as defined in claim 8 and having conductive starting strips applied to the backplate between some of said channelways, a conductive connecting strip on said ledge joined to said starting strips, and a terminal band overlying said connecting strip and secured in place by one of said base structures.

10. A fluorescent panel lamp comprising a generally flat rectangular vitreous envelope formed of a backplate and a faceplace sealed together along their margins, said backplate having a plurality of parallel interconnected grooved channelways formed therein to define a labyrinthine discharge channel, said sealed margins providing a vitreous ledge extending around said envelope, electrodes supported in the ends of said discharge channel by inleads sealed through said ledge on one side of said envelope and emerging upwardly through notches in the upper portion of said ledge, and base terminal structures seated on and attached to said marginal ledge near opposite ends thereof to overlie said notches, each base structure being in the form of an elongated block of insulating material having a generally flat front face with an aperture therethrough, generally straight side walls extending forwardly into projecting wings on each side of the front face, a top wall extending back from the front face and curving smoothly down to the rear to form the rear end wall with a curvature approximately matching that of the outermost grooved channelways in said backplate, and a pair of spaced contact pins projecting forwardly of said front face between said wings, said inleads being passed through said base structures and connected to said contact pins, and said base structures being disposed with their front faces facing each other along said ledge.

11. A fluorescent panel lamp as defined in claim 10 wherein said base structures are provided with longitudinally projecting feet at opposite ends and are secured to said ledge by clips interengaging furrowed notches in said feet and in said ledge.

12. A fluorescent panel lamp as defined in claim 10 wherein said base structures are provided with lateral tangs engaging in the valleys between adjacent grooved channelways in said backplate.

13. A base structure for an electric lamp comprising an elongated housing of insulating material having a flat front face with an aperture therethrough and side walls extending forwardly into projecting wings on each side of the front face, said housing having a blind well therein to the rear of said front face and extending upwards from the bottom wall, and an insert of insulating material accommodated in said well, said insert having terminals projecting through said aperture in the front face.

14. A base structure for an electric lamp comprising an elongated housing of insulating material having a flat front face with an aperture thcrethrough and side Walls extending forwardly into projecting wings on each side of the front face, said housing having a blind well therein to the rear of said front face and extending upwards from the bottom wall, and an insert of insulating material accommodated in said well, said insert having a pair of spaced contact pins fastened thereinto and projecting forwardly of said front face through said aperture and between'said wings.

15. A base structure for an electric lamp comprising an elongated housing of insulating material having a generally flat front face with an aperture therethrough, generally straight side walls extending forwardly into projecting wings on each side of the front face, and a top wall extending back from the front face and curving smoothly down to the rear to form the rear end wall, said housing having a blind well therein to the rear of said front face and extending upwards from the bottom wall and a blind slot to the rear of said well for the accommodation of conductors, an insert in the form of an upstanding block of insulating material accommodated in said Well, and a pair of spaced contact pins fastened into said insert and disposed to project forwardly of said front face through said aperture and between said wings,

16. A base structure as defined in claim 15 having longitudinally projecting feet at opposite ends of said housing provided with furrowed notches for engagement by a clip with an inwardly turned lip.

17. A base structure as defined in claim 15 having a tang projecting laterally from one side wall of said housing.

18. A base structure for an electric lamp comprising an elongated housing of insulating material having a generally flat front face with an aperture therethrough, generally straight side walls extending forwardly into projecting wings on each side of the front face, and a top wall extending back from the front face and curving smoothly down to the rear to form the rear end wall, said housing having a blind well therein to the rear of said front face and extending upwards from the bottom wall and a blind slot to the rear of said well for the accommodation of conductors, an insert in the form of an upstanding block of insulating material accommodated in said well, a pair of spaced contact pins fastened into said insert and disposed to project forwardly of said front face through said aperture and between said wings, and a forwardly project ing foot portion on said insert providing a seating surface for a connector at a predetermined spacing below said contact pins.

19. A base structure for an electric lamp comprising an elongated housing of insulating material having a generally fiat front face with an aperture therethrough, generally straight side walls extending forwardly into projecting wings on each side of the front face, and a top wall projecting forwardly of the front face even with said wings and extending back from the front face and curving smoothly down to the rear to form the rear end wall, said housing having a blind well therein to the rear of said front face and extending upwards from the bottom wall and a blind slot to the rear of said Well for the accommodation of conductors, an insert in the form of an upstanding block of insulating material accommodated in said well, and a pair of spaced contact pins fastened into said insert and disposed to project forwardly of said front face through said aperture between said wings and below the forward projecting portion of the top wall.

References Cited by the Examiner UNITED STATES PATENTS 2,292,060 8/1942 Reamer et al. 240-51.11 X 2,488,677 11/ 1949 McCann 240-51.11 X 2,491,237 12/1949 Way 313-333 X 2,705,310 3/1955 Hodge 313-318 X 2,774,004 12/1956 Jafle. 3,047,763 7/1962 Inman 313-109 3,138,418 6/1964 Dazley et a1. 240-51.11 X

FOREIGN PATENTS 746.669 3/ 1956 Great Britain.

GEORGE N. WESTBY, Primary Examiner. 

8. A FLUORESCENT PANEL LAMP COMPRISING A GENERALLY FLAT RECTANGULAR VITREOUS ENVELOPE FORMED OF A BACKPLATE AND A FACEPLATE SEALED TOGETHER ALONG THEIR MARGINS, SAID BACKPLATE HAVING A PLURALITY OF PARALLEL INTERCONNECTED GROOVED CHANNELWAYS FORMED THEREIN TO DEFINE A LABYRINTHINE DISCHARGE CHANNEL, SAID SEALED MARGINS PROVIDING A VITREOUS LEDGE EXTENDING AROUND SAID ENVELOPE, ELECTRODES SUPPORTED IN THE ENDS OF SAID DISCHARGE CHANNEL, AND A PAIR OF BASE TERMINAL STRUCTURES SEATED ON AND ATTACHED TO SAID MARGINAL LEDGE NEAR OPPOSITE ENDS THEREOF ON ONE SIDE OF SAID ENVELOPE, EACH BASE STRUCTURE BEING IN THE FORM OF AN ELONGATED BLOCK OF INSULATING MATERIAL HAVING A GENERALLY FLAT FRONT FACE WITH AN APERTURE THERETHROUGH, GENERALLY STRAIGHT SIDE WALLS EXTENDING FORWARDLY INTO PROJECTING WINGS ON EACH SIDE OF THE FRONT FACE, A TOP WALL EXTENDING BACK FROM THE FRONT FACE AND CURVING SMOOTHLY DOWN TO THE REAR TO FORM THE REAR END WALL WITH A CURVATURE APPROXIMATELY MATCHING THAT OF THE THE OUTERMOST GROOVED CHANNELWAYS IN SAID BACKPLATE, AND A PAIR OF SPACED CONTACT PINS PROJECTING FORWARDLY OF SAID FRONT FACE BETWEEN SAID WINGS. 